America's largest employers

About 70 percent of American companies have exactly one employee -- an army of small, efficient businesses that usually do one simple thing well. Think plumbers, graphic designers and IT consultants.

Then there are the massive corporations. From fast food chains to department stores to technology firms, these companies employ hundreds of thousands of workers while solving complex logistical problems, from transportation to supply chain management.

In order to rank America's largest corporations in terms of employment, FindTheCompany turned to public filing data, with help from Zacks Investment Research. Specifically, they focused on the 2014 10-K filing to ensure an apples-to-apples comparison.

As a result, this list will include only companies publicly traded on U.S. exchanges. That means a few foreign companies will still make the list (ex: Volkswagen), while large, non-publicly traded companies will be excluded (ex: The U.S. Department of Defense). Note that the data also excludes franchise employees.

We'll start with the overall chart, then pull out a few key observations.